Hi All,

I just started my new radiant heating floors. Instead of using the off the shelf thermostat for radiant heating floor, I decided to use the HVAC controller that we have developped in my job. This is a standard HVAC controller. The main advantage, is that is a full programmable units with the possibility of logging informations.

Now the fun part is to tune the system. I have near all the possibilitywith that system. I have an unilimted input (0-10V, Thermistor, 4-20mA) Analog Output (0-10, 4-20mA, PWM) Binary output, pid loop, etc...

I will describe my setup.

1 Thermolec 15KW (Electric)
3 floors on different story
    - 1 temp sensor in the floor. (Thermistor)
    - 1 Ambiant Temp sensor

1 floor slab (basement)
2 floors staple up

I have 3 pump (on/off). That I control too.

I will put an outside temp sensor too.

Now I would like to start to control the system. Here What I have done so far

I use a PWM to control the pump. I have use a 10Minutes of period.
I use my ambiant sensor to know how much the temperature of my floor should be to be able to maintant the setpoint (SP). To do that I use a ramp function that is define as follow

0% = SP
100% = 30 degreeC

So when the Ambiant PID calculate the error, the result of that PID determine the Degree that my floor need to be to reach the SP.

And then I have another PID that control the floor temp to it calculated SP.

I don't know if this is the way to go ?. Is there a better way of doing it ?

Is there any one here that can point me to a good documentation on how to tune and to control a radiant heating floor ?

This is a new house, so it is well insulated.

regards

Jonathan